I am asking if it is a good idea to add myself on my dad’s credit card for a year as an authorized user after I’ve already had a credit card for a few years. My dad is a difficult person, so I didn’t really want to get involved with him. However, my own account has been suffering from a lack of history. I know he has a very high credit score and history, and I understand that adding myself as an authorized user would benefit me in this. If I added myself as an authorized user but didn’t use the credit card, would that affect my credit? And after I add myself and wait for a bit, will his credit history be given to me and will that stay permanently on my account even after he removes me in the future?